Unlimited Games. How should Red play 54?
The key for Red is to make his bar-point and his 4-pt. A useful tactic is to make a point that is six away from a point you want to make. Here that is the 10-pt and 15/10, 14/10 is the right play by a long way. Any other move a blunder.
Note that 14/9, 13/9 is a very weak play. Making the 9-pt when you own the 3-pt is grossly inefficient because both points cannot be part of the same prime.